Crystals  /ˈkrɪst(ə)lz/  

Plural noun

Synonyms: Clears, brights, crags

Hindi: क्रिस्टल
Punjabi: ਸ਼ੀਸ਼ੇ

Meaning:

Crystals is a plural noun for a word "CRYSTAL."

Crystal:

1. A piece of a homogeneous solid substance having a natural geometrically regular form with symmetrically arranged plane faces.

2. Highly transparent glass with a high refractive index.

Sentence:

Today, we did experiment on "how to make crystals of copper sulfate?"